Methods and compositions using splicing regulatory proteins involved in tumor suppression

Methods and compositions for diagnosis and prognosis of mammalian carcinoma or cancer derived from primary epithelial cells and tissue fibrosis are designed using newly identified epithelial cell-type specific splicing factors ESRP1 and ESRP2, which have roles in tumor suppression. Diagnostic reagents for the detection of these splicing factors in nucleotide or protein form are useful in such methods. Therapeutic compositions can provide epithelial cells with these factors to maintain FGFR2 and assist in suppressing metastasis. A high throughput splicing assay to identify compounds that change splicing events is described. RNCP1 is also identified as a splicing factor and a diagnostic for conditions characterized by inappropriate FGFR2-splicing.